Rotatable pushbutton control of movable resistor contact and of switch connections thereto

ABSTRACT

Pushbutton control of a tuner is achieved by selectively positioning individual contacts on resistor strips formed on a baseplate together with lead wires cooperating with those resistor strips. Each pushbutton is associated with a shaft on which a resistor-contactor is adjustably mounted, the pushbutton in its known position being normally rotationally disengaged from the shaft but being rotationally engaged with the shaft when pushed inwardly. The shaft actuated by a given pushbutton moves a flexible ribbon which serves as a tuning indicator. One of the pushbuttons controls a rotary switch in which springs move into corners of an appropriately shaped opening in order to hold the switch in its various operative positions.

United States Patent lnventor Sadayoshi Iwasaki Tokyo, Japan Appl. No.869,717 Filed Oct. 27, 1969 Patented Nov. 30, 1971 Assignee AlpsElectric Co., Ltd.

Tokyo, Japan Priorities Nov. 20, 1968 Japan 43/101570;

Nov. 11, 1968, Japan, No. 43/98459 ROTATABLE PUSI-IBUTTON CONTROL OFMOVABLE RESISTOR CONTACT AND OF SWITCH CONNECTIONS THERETO l 1 Claims,19 Drawing Figs.

US. Cl 338/129, 334/7. 338/179, 338/196, 338/198 Int. Cl 1101c 9/08Field 01 Search 334/7,47, 52-54; 338/76, 128, 129, 160, 176,179,196,198, 200

[56] References Cited UNITED STATES PATENTS 3,439,292 4/1969 Henry 334/7FOREIGN PATENTS 1,462,305 11/1966 France Primary Examiner-Lewis H. MyersAssistant Examiner-Gera1d P. Tolin Attorney-James & Franklin ABSTRACT:Pushbutton control of a tuner is achieved by selectively positioningindividual contacts on resistor strips formed on a baseplate togetherwith lead wires cooperating with those resistor strips. Each pushbuttonis associated with a shaft on which a resistor-contactor is adjustablymounted, the pushbutton in its known position being normallyrotationally disengaged from the shaft but being rotationally engagedwith the shaft when pushed inwardly. The shaft actuated by a givenpushbutton moves a flexible ribbon which serves as a tuning indicator.One of the pushbuttons controls a rotary switch in which springs moveinto corners of an appropriately shaped opening in order to hold theswitch in its various operative positions.

PATENTEnun v so l97| 3, 624. 582 sum 2 or 5 INVENTOR SADAVOSH/ IWASAK/ATTORNEY 5 PATENTEnuuv 30 Ian SHEET 3 OF 5 INVENTOR 5A DAYOSH/ [WA 54 K/BYO W4; ATTORNEY PATENTEnunv 30 I971 3,624,582

sum u [If 5 INVENTOR 8A DAYOSH/ IWASA Kl ATTORNEY PATENTEnunv 30 I9?! 3624, 5 82 sum 5 ar 5 INVENTOR 5A DAVOSl-l/ IWASA Kl t aw/MM ATTORNEYROTATABLE PUSHBUTTON CONTROL OF MOVABLE RESISTOR CONTACT AND OF SWITCHCONNECTIONS THERETO This invention generally relates to control devices,and more particularly to such devices which include variable rev sistorsor voltage dividers and are employed for a tuning circuit utilizing acapacitive diode (varactor diode) or the like.

The capacitive diode is a kind of semiconductor element wherein thethickness of the scarcity layer is varied in accordance with themagnitude of the voltage applied thereto, whereby the capacitance iscorrespondingly varied.

When this kind of diode is employed as a static variable capacitor,various kinds of tuning circuits may be constituted.

As is apparent from the above, when it is desired to use the capacitivediode as a variable capacitor, a control device such as a voltagedivider for controlling the voltage applied to the diode is required.

Furthermore, it is also required that an indicator be provided for thecontrol device in order to indicate the tuning condition of the circuit.This invention is directed to an improved construction of such a controldevice including an indicator.

A control device of this general kind is shown in French Pat. No.1,462,305. That control device comprises a series of variable resistorsprovided in correspondence to a series of channels, all of the variableresistors being formed in one unit module. A plurality of operatingshafts are provided the number of which corresponds to the number of thechannels. The variable resistors having sliding contact members, andthere is mechanism for converting the movement of the operating shaftsinto sliding motion of the contact members, whereby the individualvariable resistors are adjusted by means of their respective operatingshafts to vary their output voltages.

However, the control device described in the French patent hasshortcomings, and it is the primary object of the invention to providean improved construction of the control device whereby all of thoseshortcomings are substantially eliminated.

Another object of the present invention is to provide a control devicewherein an indicator plate is freely detachably mounted on the baseplateso that the control device may also be employed as a thinner-typedevice.

Still another object of the invention is to provide an improved controldevice wherein a connector may be employed for connecting the lead wiresof the control device to an outside circuit.

Still another object of the invention is to provide a novel constructionof an AFC switch.

Still additional object of the invention is to provide a control deviceincluding an AFC switch and the above-described voltage dividers in onecasing.

These and other objects of the invention can be attained by an improvedconstruction of the control device including a plurality of variableresistors the number of which corresponds to the number of the channels,said variable resistors being formed into a single module, a number ofoperating shafts also corresponding to the number of channels, slidingcontact members for the variable resistors, and mechanisms forconverting the rotation of said operating shafts to sliding movement ofsaid sliding contact members and whereby a voltage applied to theoutside circuit is controlled by the sliding movement of the slidingcontact member which is driven by the rotation of the operating shaft;the improvement comprising two lead wires connected to the ends of thevariable resistors and one central tap lead wire connected to saidsliding contact member, when it is required, by means of a switchingmechanism, all of said lead wires being formed in a single module.

Another feature of the present invention is that the ends of said twolead wires and one center tap lead wire, all formed in a single module,are arranged on one side of an insulating plate so that the ends of thelead wires are reliably spaced from one another by equal distances.

Still another feature of the present invention is that the rotatingmovement of the operating shaft is converted into the sliding movementof the sliding contact member by mechanism including a guiding portiondirectly coupled to each of the operating shafts, said guiding portionextending above and parallel to the variable resistors and soconstructed that when a contact member slides along a correspondingguiding portion of an operating shaft, the contact member slides alongone of the variable resistors in a reliable contacting relationshipthereto.

Still another feature of the present invention is that there areprovided, on the ends of the operating shafts opposite to said endscoupled to the guiding lines for the sliding contact members, aplurality of sleeve-shaped knobs normally rotationally disengaged fromtheir respective operating shafts and axially movable for apredetermined length along said shafts, the knobs being so constructedthat when they are pushed rearwardly for the predetermined length alongthe shafts, they rotationally engage with the operating shafts, afterwhich the knobs and the operating shafts may be rotated in unison.

Still another feature of the invention is that on the rear side of theknobs there are drum members which are fixed to the knobs, slide alongthe operating shafts, and have conical surfaces. A locking plate isarranged in such a manner that the tip of the front edge thereof isurged against the conical surfaces of said drums, said knobs and drumsbeing pushed back toward the forward ends thereof by means of retractingsprings provided respectively on said operating shafts. In the normalcondition the knobs and drums are retracted to the forward positions onthe operating shafts and are thus retained in the nonoperable condition.When a knob is pushed rearwardly, the forward end of said drum membercoupled to said knob is engaged and locked by said locking plate,whereby the knobs and drum are maintained in the rearward position wherethey can be rotated in unison with the operating shaft.

Still another feature of the present invention is that at the rear sideof each drum member a movable plate is arranged on the operating shaftto be reciprocable along the operating shaft together with each saidknob and drum. Two mutually connected contacts are provided on saidmovable plate, the contacts being slidable on the insulating plate whenthe movable plate is reciprocated along the operating shaft. A pluralityof fixed contacts are provided on said insulating plate, a pair of thefixed contacts being connected together by said two movable contactswhen the knob is maintained in the reward position, one of the pair offixed contacts being electrically connected to said central tap leadwire, the other of the pair of the fixed contacts being electricallyconnected to the appropriate one of the operating shafts. Hence aswitching mechanism is formed by the movable contacts and said one pairof the fixed contacts.

Still another feature of the invention is that in the abovedescribedvoltage control device, comprising an insulating plate on which arelocated said module-formed resistors, lead wires, a central tap leadwire, and said fixed contacts, a plurality of operating shafts areprovided, each coupled to a guiding portion for a sliding member andextending above said insulating plate, said operating shaft having aknob and a drum at the forward end thereof, a locking plate for lockingsuch drums on said plurality of operating shafts, and a movable platehaving interconnected contacts mounted slidably on each of the operatingshafts. ln addition a plurality of windows are formed in the cover ofthe control device, each of said sliding contact members having aprojection at an end opposite to that which slides along thecorresponding resistor, and said projection is so arranged that it maybe exposed in one of said element cover, thus constituting an indicatorwhich displays the adjusted conditions of the control device by theexposed positions of the projections.

. Still another feature of the present invention is that the indicatorplate is freely detachably mounted on the housing at a position near thefront end portion thereof, a plurality of windows being formed in thatplate as described above, said indicator plate being oriented to make adesired angle with the axial direction of the operating shafis. Groovesare formed on both sides of each window in the plate and a flexibleribbon is guided by said grooves, one end of each ribbon being fixed toa corresponding sliding member, whereby the controlled positions of thesliding contact members along the variable resistors may be read fromthe positions of the other ends of the ribbons in said windows in theindicator plate.

An additional feature of the present invention is that one of theoperating shafts is provided with a rotary switch including a cam platerotated by said operating shaft and operable to open or close thecontacts instantaneously with the aid of the reversible spring. Theabove-described objects, features, and means for achieving these objectsand features of the present invention will be made apparent from thefollowing description with respect to preferred embodiments thereof whenread together with the accompanying drawings, wherein:

FIG. 1 is a sectional view showing a construction of a control deviceconstituting one embodiment of the present invention;

FIG. 2 is a perspective view, particularly broken away, of one part ofthe control device shown in FIG. 1 illustrating the portion in moredetail;

FIG. 2A and 2B are enlarged detail cross-sectional views showing thepushbutton-operating shaft connections, FIG. 2A showing the pushbuttonin a disconnected position relative to the shaft and FIG. 28 showing thepushbutton in a connected position relative to the shaft;

FIG. 3 is another perspective view, much enlarged, showing the relationbetween the resistors and the sliding contact members in the controldevice shown in FIG. 1;

FIG. 4 is still another perspective view illustrating the switchingmechanism in the control device shown in FIG. 1;

FIG. 5 is an outside perspective view of the device shown in FIG. 1;

FIG. 6 is a sectional view, partly broken away, indicating theconstruction of the indicator portion in the control device shown inFIG. 1;

FIG. 7 is an enlarged perspective view indicating in more detail theconstruction of the indicator portion of the device shown in FIG. 1;

FIG. 7A is a cross sectional view of the sliding member, taken alongtheline 7A-7A of FIG. 7;

FIG. 8 is a sectional view showing one part of another example of thecontrol device of this invention which has an indicator plate inclinedat a desired angle to the vertical;

FIGS. 9A, 9B and 9C are fragmentary perspective views showingapplications of the control device of the present invention toreceivers;

FIG. 10 is a perspective view of an AFC switch also constituting onepart of the present invention;

FIG. 11 is an exploded view of the AFC rotary switch shown in FIG.10-indicating the construction in more detail; and

FIGS. 12A, 12B and 12C are views explaining the operation of the rotaryswitch shown in FIG. 10 Referring now to FIG. 5 showing an outside viewof a control device constituting an embodiment of the present invention,reference numeral 1 designates an element cover and reference numeral 2designates a front frame, both constituting a casing for a controldevice. Numeral 3 designates an indicator plate, numeral 4 designates aplurality of knobs arranged to be projecting from the front plate 5 ofthe casing, the number of the knobs corresponding to the number ofchannels to be turned, and numeral 6 designates a knob for an AFCswitch. On the indicator plate 3, a plurality of vertically extendingwindows 7, one for each channel to be tuned, are provided. On thehorizontal surface of the element cover 1, a plurality of windows 8 areprovided. Numeral 9 designates flexible ribbons, one end of each of theribbons being fixed to a sliding member exposed through each of thewindows 8, each ribbon extending to one of the windows 7 on theindicator plate 3.

Referring to FIG. 1 through FIG. 5 indicating internal construction ofthe control device according to the present invention, there is provideda printed circuit board or plate 10, on which are further provided aprinted circuit board or plate 10, on which are further providedresistors 11, one for each channel to be turned (only one of them isshown), printed paths 12a and 12b, made of, for instance, copper andacting as lead wires connected to both ends of the resistors 11, anotherprinted path 12c employed as another lead wire for a central tapconnected to a sliding member 15 (hereinafter described) slidable alongeach of the resistors 11, a plurality of fixed contacts 13a connected tothe printed path 120, and a plurality of fixed contacts 13b to beconnected to the fixed contacts and to be electrically connected to thesliding members through the operating shafts (also describedhereinafier). These fixed contacts 13a and 13b adapted to be connectedto the fixed contacts 13a (through contacting member 20) and to thesliding members 15 (through the operating shafts 14), all as describedhereinafter. The contacts 13b may be in two parts, one formed on theboard 10 and the other, defined by a resilient conductive strip,extending from the' part on the board 10 up to and engaging thecorresponding shaft 14 without making contact with the path 120.

The printed circuit board or plate 10 is placed between the front plate5 of the frame 2 and the rear wall 5a thereof so that the plate 10 alsoforms a bottom plate for the casing. Therefore, the surface of the plate10 on which the above-described resistors 11 and the paths 12a, i217 and12c are provided is the upper surface thereof and the plate 10 isarranged so that all of the resistors 11 extend between the front plate5 and the rear wall 5a.

Numeral 14 designates the operating shafts which also extend between thefront plate 5 and the rear wall 5a (passing freelythrough intermediatewall 5b) and are rotatable about their axes. The number of shafts 14corresponds to the number of channels to be tuned. About one-half of thelength of the operating shafts 14 is formed with screw threads 40defining guiding portions for the sliding members 15 are therebyprovided, those guiding portions 14' extending above, along and parallelto the resistors 11. The sliding member 15 has a contact point engagingand sliding along a corresponding resistor 11 when the operating shaft14 is rotated around its axis. The construction of the sliding member15, and its manner of attachment to the screw-threaded portion 14' ofthe shaft 14 is best shown in FIGS. 7 and 7A. The sliding member 15comprises a housing 130 provided with a longitudinally extending passage131 extending therethrough and with slots 133 formed in the lowersurface I35 of the housing 130 and communicating with the passage 131.The conductive contact strip 137 is arcuately bent and has end portions139 which are adapted to pass through the slots 133 into the passagel3l, those end portions having arcuate recesses 141 formed therein. Theshaft 14, and in particular the screwthreaded portions 14' thereof, isadapted to extend through the passage 13!, the arcuate recesses 141 inthe contact strip 137 being pressed up against the shaft 14 so as toengage with the screw-threaded portion 14' thereof, the contact strip137 being compressed between the shaft 14 and the corresponding resistor11 on the circuit board 10. Hence as the shafts 14 are rotated thecorresponding slidable members 15 will be moved axially therealong. Thisis, of course, but one way in which the appropriate mounting of theoperative connection to the sliding members 15 may be achieved.

On the ends of the operating shafts 14 projecting forwardly from thefront plate 5 are attached the above-described knobs 4 which are freelyshiftable along the longitudinal direction of the shafts 14. When theknobs 4 are pushed to the utmost rearward position along the operatingshafts 14 (to the right as viewed in FIG. 1), the knobs 4 are rotatablyengaged with the shafts 14, after which the knobs 4 and the shafts 14will rotate together.

The knobs 4 are fixedly coupled to drums 16 which have conical portionsand are provided inside of the front plate 4 so that the drums l6 arealso freely shiftable over the operating shafts M. The front edge of alocking plate l7 engages the conical surfaces of the drums. As isapparent from FIG. 2, the locking plate 17 is mounted between twosidewalls of the frame 2 so as to be freely swingably around its axis,and a biasing spring 18 urges the locking plate 17 so that the frontedge thereof is pressed against the conical surface of the drum 16. Thedrum 16 should be so arranged that the largest diameter end of theconical portion is located adjacent to the inside surface of the frontplate 5.

Rearwardly against the drum 16, a movable plate 19 is provided for eachof the operating shafts 14, each plate 19 being freely slidable on itsshaft 14. On the downwardly projecting end 19a of the movable plate 19,a contacting member 20v is fixedly attached. 0n the contacting member20, a contacting surface 20a is formed which contacts with the uppersurface of the printed circuit plate 10. For allowing the axial movementof the projecting end 190 along the operating shaft 14 and forrestricting its rotation when the shaft 14 is rotated, a groove 21 isprovided on the printed circuit plate at the corresponding position, inwhich the end 19a is slidably received (see FIG. 4).

Rearwardly of the movable plate 19 on the operating shaft 14, a biasingspring 22 is provided which urges the knob 4, drum 16 and the movableplate 19 forwardly.

FIGS. 2, 2A and 2B illustrate one structure by means of which therequisite mounting and operative connection of the knobs 4 on the shaft14 is disclosed. The knob 4, with itsassociated drum 16, is providedwith an axial passage 4 through which the shaft 14 is slidable. Thatshaft 14, at its outer end, is provided with a tip portion 14" ofreduced diameter joined to the shaft proper 14 by a tapered section 14"which is toothed. The knob 4 is provided near its outer end with areduced size passage 4" which communicates with the main passage 4' bymeans of an outwardly tapered section 4" which is toothed in a matingfashion to that of the shaft portion 14". When the spring 22 acts on theplate 19 to move the knob4 and its associated drum forwardly, or to theleft as shown in FIG. 2, the tapered knob and shaft portions 4" and 14"are separated and only the tip of the shaft portion 14" is receivedwithing the knob passage 4", as shown in FIG. 2A. Under thesecircumstances rotation of the knob 4 will not be transmitted to theshaft 14. When, however, the knob 4 is pushed inwardly against theaction of the spring 22 to its position illustrated in FIG. 28, wherethe locking plate 17 has engaged behind the drum 16, the matinglytoothed tapered surfaces 14' and 4" of the shaft and knob respectivelywill en gage one another, after which rotation of the knob 4 will betransmitted to the shaft 14 and will drive the latter in rotation.

in the above described control device, when a constant voltage isapplied between the lead wires 12a and 12b, that voltage is then appliedacross the resistors 11. if one of the knobs 4 is pushed rearwardly, thefront edge of the locking plate 17 is lifted upwardly along the conicalsurface of the drum 16, and ultimately the forward end surface of thedrum 16 is locked by the downwardly directing tip of the locking plate17. In this way, forward movement of the knob 4 and the drum 16 due tothe biasing spring 22 is blocked.

At this time, the movable plate 19 together with the drum 16 is alsoshifted along the operating shaft 14, and if the drum is blocked asdescribed above, the movable contact provided on the movable plate 19contacts with both of the fixed contacts 13a and 13b, whereby thecontacts 130 and 13b are electrically connected together.

On the fixed contact 13b, there is provided a conductive plate 13b (seeFIGS. 4) mechanically and electrically contacting the operating shaft14. Accordingly, if an external element (such as a varactor diode) isconnected between the lead wires 12c and 12b (or 12a), a voltage createdbetween the lead wire ab and the sliding member on the resistor 11 isapplied across that external element. To be more specific, when the knob4 is pushed rearwardly, an electric circuit through the external elementis actuated.

Thereafter, the knob 4 may be rotated, rotating the operat ing shaft 14in a desired direction. As a result the sliding member 15 is shiftedalong the guiding portion 14 of the operating shaft 14 so that thecontacting position thereof along the resistor 11 is changed. Accordingto the adjusted position of the sliding member 15, the potentialdifference between the lead wires 12b and 12c is changed. That is, thepotential difference is controlled by turning the knob 4 through adesired angle.

When a varactor diode is connected between the lead wire 12b and 12c,the capacitance of the varactor diode is thus controlled by turning aknob 4 in this control device.

Furthennore, since the lead wires 12a, 12b and are arranged in specifiedsequence at a predetermined distance from one another at the edge of theprinted circuit plate 10, the connection of this device to the outsidecircuit may be carried out simply inserting the circuit plate 10 into aconventional printed circuit connector (not shown).

In this example, because the contact point of the sliding member 15 andthe conducting plate 13b are electrically connected through theoperating shaft 14, 14' at least the surface portions of the operatingshafts 14, 14' must be made of an electrically conductive material.

When it is desired to release the control device from its operatingcondition, a knob 4 for any other channel should be pushed slightly. inthis way the tip of the locking plate 17 is lifted along the conicalsurface of the drum 16 belonging to the depressed shaft 14 against thespring force of the biasing spring 18, and the locking of the operatingshaft 14 is thereby released. The knob 4, drum l6 and the movable plate19 of the operating shaft 14 will then be returned to their originalprojected position by the action of the biasing spring 22, whereby themovable contact 20a will be disengaged from the fixed contacts 13a and13b, and the voltage applied across the lead wires 12b and 12c will benullified.

The construction and operation of the indicator will now be describedwith reference to FIGS. 5 through 7.

As As already described, the indicators comprise an indicator plate 3,windows 7 provided on the indicator plate 3, and flexible ribbons 9movable up and down inside the windows 7. Since the indicator plate 3 isdetachably mounted on the frame 2 by means of, for instance, engageablejoints or machine screws, the indicator plate 3 may be removed ifdesired.

As described before, the number and locations of the windows 7 are sodetermined by the number of the channels and the locations of thewindows 8 provided in the element cover 1 for exposing the slidingmembers 15. On both sides of each of the windows 7, vertically directinggrooves 71 are provided in parallel with the windows 7, and in thesegrooves 71, a flexible ribbon 9 is inserted so that each ribbon 9 isfreely slidable inside of its groove 71.

It should be noted that the ends 91 of of the 9 can be seen through thewindows 7, and that the other ends 92 thereof are fixed to the upper endportions 15' of the sliding members 15. To be more particular, theribbons 9 are bent at the positions where the ribbons are led out of thegrooves 71 and received in other grooves 81 which are provided on bothsides of the windows 8 in alignment with the grooves 71.

With this arrangement, when the sliding member 15 is shifted as a resultof the rotation of the corresponding knob 4, the ribbon 9 is movedtogether with the sliding member 15, and the movement of the ribbon 9can be detected by the location of the end 91 of the ribbon 9 as seen inthe window 7.

Accordingly, if a graduated scale is provided on one side of the windowor windows 7 or on the front panel of a casing wherein the controldevice is encased, the rotation of the knob 4 can be adjusted byobserving the location of the end 91 of the ribbon 9 relative to thegraduated scale.

FIG. 8 shows another example of the control device, wherein the anglebetween the indicator plate 3 and the frame 2 is altered from that ofthe above-described example. Since all of the component parts and theconstruction are similar to the first embodiment of the invention shownin FIGS. 1 through 7, except the above-described feature of thedifferent angle, further description of this embodiment is not required.

In FIG. 9, there is indicated ah application of this control device in atelevision receiver, wherein the embodiment of the invention shown inFIGS. 1 through 7 is combined in the receiver as shown in FIG. 9A andthe embodiment of FIG. 8 is combined in the receiver as shown in FIG.9B. It is seen that, in the case of FIG. 9A, the knobs 4 and theindicating windows 7 are arranged in the same plane, and, in the case ofFIG. 9B, the plane including the indicating windows 7 and the planewherein the knobs are arranged are spanning an angle.

As described before, when the indicator plate 3 and the ribbons 9 areremoved, the control device can be used per se as a thin-type controldevice. In such an application, the exposed ends of the sliding members15 in the windows 0 in the element cover 1 act as an indicator in thiscontrol device. FIG. 9C indicates this kind of application. It should benoted that the plane including the windows 8 and the plane in which theknobs 4 are arranged are intersecting perpendicular.

Referring again to FIG. 5, there is indicated a knob 6 for operating anAFC switch which is in itself a rotary switch. The detailed constructionof the AFC switch will now be described with reference to FIGS. 10, Illand 112.

In a frame body 101, there are provided three engaging positions for aspring which correspond to three apices of a triangle. The firstengaging position 102 engages with one leg 105a of a spring 105 bentinto a V-shaped configuration. The second and third engaging positions103 and 104 engage with an intermediate portion of the other leg of thespring 105 as will be described hereinafter. The end 105b of the otherleg of the spring 105 engages with a bifurcated engaging arm III of anoperating cam 106 which is freely rotatably mounted on the frame body101.

The circumferential surface of the operating cam 106 contacts with aresilient contact piece 107, one end of which is fixed to an insulatingplate (not shown) and the other end of which is left free. Theintermediate portion between the fixed end and the free end of thecontact piece 107 is curved as designated by numeral 114.

At another position on the insulating plate opposing the free end of thecontact piece 107, a fixed contact 110 is provided. When the curvedportion 114 of the contact piece 107 is not depressed by a projection112 of the operating cam plate 106, the free end of the contact piece107 does not contact with the fixed contact 110 (see FIG. 12C). when thecurved portion 114 is depressed, the free end of the contact piece 107contacts with the fixed contact 110, whereby the switch is closed asshown in FIG. 12A.

The operating cam plate 106 has a central hole 113 which is fixed to arotating shaft 103. The rotating shaft 108 is freely rotatably mountedon the frame body 101 through a hole 109. As is previously described,the three engaging positions 102, 103, and 104 form a triangle inside ofwhich has been cut away so that a triangular hole 115 is bored throughthe frame body 101. Between the engaging positions 103 and 104 a convexguiding edge 116 toward the engaging position 102 is provided. anintermediate portion 105: of the V-shaped spring 105 is guided along theconvex guide edge 116.

When the rotating shaft 108 is rotated by means of a knob 6, the switchposition may be shifted from its ON" position indicated in FIG. 12Athrough an intermediate position as shown in FIG. 128 to the OFF"position indicated in FIG. 12C.

In this case, 'since the spring 105 is once compressed at theintermediate position (FIG. 1213) through the convex guide edge 116,further turning of the knob 6 exceeding the maximum convex point allowsthe V-shaped spring 105 to expand again, and the leg 1050 is rapidlyshifted to another engaging position 104. As a result, the operating camplate 106 is quickly rotated, and the projected portion 112 of the camplate 106 is rapidly released from the curved portion 114 of theresilient contact piece 107. The contact piece 107 thereby interruptsthe engagement of the contact piece 107 with the fixed contact 110.

If it is desired to shift the rotary switch from its OFF" position (FIG.12C) on the ON" position (FIG. 12A), the rotattion by means of the knob6.

It will be apparent that the rotary switch indicated in FIGS. 10, 11 and12 may be employed as an AFC switch which is indicated merely by a knob7 in FIGS. 1 through 8. In such a case, the frame body 101 correspondsto the front plate 5 of the frame body 2, and the insulating platecorresponds to the printed circuit plate 10.

With the above-described construction, a control device having an AFCswitch, an indicator for indicating the positions of the slidingmembers, and lead wires which may be connected to an outside circuitthrough a standard printed circuit connector may be obtained.

Although the present invention has been described with respect topreferred embodiments thereof, it will be apparent that variousmodifications may be made without departing the scope and spirit of thepresent invention.

lclairn:

1. In a control comprising a series of variable resistors provided incorrespondence to a series of channels to be tuned, said resistors beingconstructed in a single module, a plurality of operating shafts of anumber corresponding to that of the channels, a plurality of slidingmembers provided respectively for said variable'resistors, and amechanism for converting the operation of said operating shafts to themovement of the corresponding sliding members, so that a voltage iscontrolled by controlling any one of said variable resistors through theoperation of said operating shaft; the improvement comprising: abaseplate consisting of an insulating material on which are provided, inthe form of a module, two lead wires connected to both ends of saidvariable resistors respectively, a tap lead wire adapted to be connectedthrough respective electric switch means to said sliding members, and anumber of pairs of fixed contacts on said base corresponding to saidchannels respectively; a plurality of rotatable operating shaftscorresponding to said channels respectively arranged in a spaced apartrelationship from said variable resistors, each of said rotatableoperating shafts being provided with screw threads on a part locatedabove said variable resistors, so that a guiding portion thereof isformed; a plurality of sliding members mounted respectively on saidrotatable operating shafts and shifted by the rotation of said operatingshafts along said guiding portions; and switch means cooperating witheach of said operating shafts for opening or closing a circuit betweenthe corresponding pair of fixed contacts, one of said pair of contactsbeing connected to said tap lead wire and the other of said pair beingconnected to said sliding member through said operating shaft; whereby avoltage obtained between said tap lead wire and one of said two leadwires can be controlled by rotating said operating shafts.

2. A control device as defined in claim 1, wherein terminals of said twolead wires and one tap lead wire are arranged adjacent one edge of saidbaseplate with an equal distance maintained therebetween.

3. A control device as defined in claim 1, further comprising: aplurality of knobs provided on the forward ends of said operating shaftsso that the knobs can be shifted along said shafts for a predetermineddistance, said knobs engaging with said shafts at the time the knobs arepushed along the shafts for a maximum distance, so that thereafter theknobs and the shafts are rotated in unison; a plurality of drums eachhaving a conical surface portion and coupled to a knob at its largestdiametrical end of said conical portion, said drums being slidablemounted on said operating shaft at a location rearwardly adjacentthereto; a locking plate urged against said conical surfaces of saiddrums; movable plates mounted on said shafts and coupled to said knobs;a movable contact formed at the lower end of each of said movable platesand electrically connecting said two fixed knobs provided on saidbaseplate at the time one of said knobs is pushed rearwardly along saidoperating shaft, so that said switching means is thereby constituted;and a biasing spring for urging each of said knobs, drums, and movableplates along said operating shaft.

4. A control device as defined in claim 3, wherein an indicatingmechanism for indicating control states of said control device iscomposed of: a cover plate provided over said operating shafts; windowsprovided in said cover plate and having a length corresponding to themoving stroke of said sliding members; and projecting portions of saidsliding members exposed from said windows.

5. A control device as defined in claim 1, wherein an indicatingmechanism for indicating condition of said control device comprises: acover plate provided over said operating shafts; windows provided insaid cover plate having a length corresponding to the moving stroke ofsaid sliding members;

an indicator plate disposed upwardly from said operating shafts andmaking a predetennined angle with said operational shafts; windows insaid indication plate corresponding to the above mentioned windows insaid cover plate; and. flexible ribbons each extending along one of saidwindows in the indicating plate and also along the corresponding windowin said cover plate in sliding manner, and one end thereof being fixedto a corresponding one of the sliding members; whereby the movement ofsaid sliding members on the operating shafts can be indicated by themovement of ribbons in said windows in the indicating plate attached onthe front part of the control device.

6. A control device as defined in claim 5, wherein each'of said ribbonsis received in a groove provided beside each window and is movable alongsaid groove.

7. In a control device comprising a series of variable resistorsprovided in correspondence to a series of channels to be tuned, saidresistors being constructed in a single module, a

, plurality of operating shafts of a number corresponding to that of thechannels, a plurality of sliding members provided respectively for saidvariable resistors, and a mechanism for converting the operation of saidoperating shafts to the movement of the corresponding sliding members,so that a voltage is controlled by controlling any one of said variableresistors through the operation of said operating shaft; the improvementcomprising a baseplate consisting of an insulating material on which areprovided, in the form of a module, a lead wire connected to an end ofsaid variable resistors respectively, a tap lead wire adapted to beconnected through respective electric switch means to said slidingmembers, and a number of pairs of fixed contacts on said basecorresponding to said channels respectively; a plurality of rotatableoperating shafts corresponding to said channels respectively arranged ina spaced apart relationship from said variable resistors, each of saidrotatable operating shafts being provided with screw threadson a partlocated above said variable resistors, so that a guiding portion thereofis formed; a plurality of sliding members mounted respectively on saidrotatable operating shafts and shifted by the rotation of said operatingshafts along said guidin'g portions; and switch means cooperating witheach of the said operating shafts for opening or closing a circuitbetween the corresponding pair of fixed contacts. one of said pair ofcontacts being connected to said tap lead wire and the other of saidpair being connected to said sliding member through said operatingshaft; whereby the resistance between said end of said variable resistorand said tap lead wire can be controlled by rotating said operatingshafts.

8. A control device as defined in claim 7 further comprising: aplurality of knobs provided on the forward ends of said operating shaftsso that the knobs can be shifted along said shafts for a predetermineddistance, said knobs engaging with said shafts at the time the knobs arepushed along the shafts for a maximum distance, so that thereafter theknobs and the shafts are rotated in unison; a plurality of drums eachhaving a conical surface portion and coupled to a knob at its largestdiametrical end of said conical portion, said drums being slidablymounted on said operating shaft at a location rear-' formed at the lowerend of each of said movable plates and electrically connecting two fixedcontacts provided on said baseplate at the time one of said knobs ispushed rearwardly along said operating shaft, so that said switchingmeans is thereby constituted; and a biasing spring for urging each ofsaid knobs, drums, and movable plates along said operating shaft.

9. A control device as defined in claim 8, wherein an indicatingmechanism for indicating control states of said control device iscomposed of: a cover plate provided over said operating shafts; windowsprovided in said cover plate and having a length corresponding to themoving stroke of said sliding members; and projecting portions of saidsliding members exposed from said windows.

10. A control device as defined in claim 7, wherein an indicatingmechanism for indicating conditionof said control device comprises: acover plate provided over said operating shafts; windows provided insaid cover plate having a length corresponding to the moving stroke ofsaid sliding members; an indicator plate disposed upwardly from saidoperating shafts and making a predetermined angle with said operationalshafts; windows in said indicating plate corresponding to theabove-mentioned windows in said cover plate; and flexible ribbons eachextending along one of said windows in the indicating plate and alsoalong the corresponding window in said cover plate in sliding manner,and one end thereof being fixed toa corresponding one of the slidingmembers; whereby the movement of said sliding members on the operatingshafls can be indicated by the movement of ribbons in said windows inthe indicating plate attached on the front part of the control device.

11. A control device as defined in claim 10, wherein each of saidribbons is received in a groove provided beside each window and ismovable along said groove.

i i i I l

1. In a control device comprising a series of variable resistorsprovided in correspondence to a series of channels to be tuned, saidresistors being constructed in a single module, a plurality of operatingshafts of a number corresponding to that of the channels, a plurality ofsliding members provided respectively for said variable resistors, and amechanism for converting the operation of said operating shafts to themovement of the corresponding sliding members, so that a voltage iscontrolled by controlling any one of said variable resistors through theoperation of said operating shaft; the improvement comprising: abaseplate consisting of an insulating material on which are provided, inthe form of a module, two lead wires connected to both ends of saidvariable resistors respectively, a tap lead wire adapted to be connectedthrough respective electric switch means to said sliding members, and anumber of pairs of fixed contacts on said base corresponding to saidchannels respectively; a plurality of rotatable operating shaftscorresponding to said channels respectively arranged in a spaced apartrelationship from said variable resistors, each of said rotatableoperating shafts being provided with screw threads on a part locatedabove said variable resistors, so that a guiding portion thereof isformed; a plurality of sliding members mounted respectively on saidrotatable operating shafts and shifted by the rotation of said operatingshafts along said guiding portions; and switch means cooperating witheach of said operating shafts for opening or closing a circuit betweenthe corresponding pair of fixed contacts, one of said pair of contactsbeing connected to said tap lead wire and the other of said pair beingconnected to said sliding member through said operating shaft; whereby avoltage obtained between said tap lead wire and one of said two leadwires can be controlled by rotating said operating shafts.
 2. A controldevice as defined in claim 1, wherein terminals of said two lead wiresand one tap lead wire are arranged adjacent one edge of said baseplatewith an equal distance maintained therebetween.
 3. A control device asdefined in claim 1, further comprising: a plurality of knobs provided onthe forward ends of said operating shafts so that the knobs can beshifted along said shafts for a predetermined distance, said knobsengaging with said shafts at the time the knobs are pushed along theshafts for a maximum distance, so that thereafter the knobs and theshafts are rotated in unison; a plurality of drums each having a conicalsurface portion and coupled to a knob at its largest diametrical end ofsaid conical portion, said drums being slidably mounted on saidoperating shaft at a location rearwardly adjacent thereto; a lockingplate urged against said conical surfaces of said drums; movable platesmounted on said shafts and coupled to said knobs; a movable contactformed at the lower end of each of said movable plates and electricallyconnecting said two fixed knobs provided on said baseplate at the timeone of said knobs is pushed rearwardly along said operating shaft, sothat said switching means is thereby constituted; and a biasing springfor urging each of said knobs, drums, and movable plates along saidoperating shaft.
 4. A control device as defined in claim 3, wherein anindicating mechanism for indicating control states of said controldevice is composed of: a cover plate provided over said operatingshafts; windows provided in said cover plate and having a lengthcorresponding to the moving stroke of said sliding members; andprojecting portions of said sliding members exposed from said windows.5. A control device as defined in claim 1, wherein an indicatingmeChanism for indicating condition of said control device comprises: acover plate provided over said operating shafts; windows provided insaid cover plate having a length corresponding to the moving stroke ofsaid sliding members; an indicator plate disposed upwardly from saidoperating shafts and making a predetermined angle with said operationalshafts; windows in said indicating plate corresponding to theabove-mentioned windows in said cover plate; and flexible ribbons eachextending along one of said windows in the indicating plate and alsoalong the corresponding window in said cover plate in sliding manner,and one end thereof being fixed to a corresponding one of the slidingmembers; whereby the movement of said sliding members on the operatingshafts can be indicated by the movement of ribbons in said windows inthe indicating plate attached on the front part of the control device.6. A control device as defined in claim 5, wherein each of said ribbonsis received in a groove provided beside each window and is movable alongsaid groove.
 7. In a control device comprising a series of variableresistors provided in correspondence to a series of channels to betuned, said resistors being constructed in a single module, a pluralityof operating shafts of a number corresponding to that of the channels, aplurality of sliding members provided respectively for said variableresistors, and a mechanism for converting the operation of saidoperating shafts to the movement of the corresponding sliding members,so that a voltage is controlled by controlling any one of said variableresistors through the operation of said operating shaft; the improvementcomprising: a baseplate consisting of an insulating material on whichare provided, in the form of a module, a lead wire connected to an endof said variable resistors respectively, a tap lead wire adapted to beconnected through respective electric switch means to said slidingmembers, and a number of pairs of fixed contacts on said basecorresponding to said channels respectively; a plurality of rotatableoperating shafts corresponding to said channels respectively arranged ina spaced apart relationship from said variable resistors, each of saidrotatable operating shafts being provided with screw threads on a partlocated above said variable resistors, so that a guiding portion thereofis formed; a plurality of sliding members mounted respectively on saidrotatable operating shafts and shifted by the rotation of said operatingshafts along said guiding portions; and switch means cooperating witheach of the said operating shafts for opening or closing a circuitbetween the corresponding pair of fixed contacts, one of said pair ofcontacts being connected to said tap lead wire and the other of saidpair being connected to said sliding member through said operatingshaft; whereby the resistance between said end of said variable resistorand said tap lead wire can be controlled by rotating said operatingshafts.
 8. A control device as defined in claim 7 further comprising: aplurality of knobs provided on the forward ends of said operating shaftsso that the knobs can be shifted along said shafts for a predetermineddistance, said knobs engaging with said shafts at the time the knobs arepushed along the shafts for a maximum distance, so that thereafter theknobs and the shafts are rotated in unison; a plurality of drums eachhaving a conical surface portion and coupled to a knob at its largestdiametrical end of said conical portion, said drums being slidablymounted on said operating shaft at a location rearwardly adjacentthereto; a locking plate urged against said conical surfaces of saiddrums; movable plates mounted on said shafts and coupled to said knobs;a movable contact formed at the lower end of each of said movable platesand electrically connecting two fixed contacts provided on saidbaseplate at the time one of said knobs is pushed rearwardly along saidoperating shaft, so that said switching means is thereby coNstituted;and a biasing spring for urging each of said knobs, drums, and movableplates along said operating shaft.
 9. A control device as defined inclaim 8, wherein an indicating mechanism for indicating control statesof said control device is composed of: a cover plate provided over saidoperating shafts; windows provided in said cover plate and having alength corresponding to the moving stroke of said sliding members; andprojecting portions of said sliding members exposed from said windows.10. A control device as defined in claim 7, wherein an indicatingmechanism for indicating condition of said control device comprises: acover plate provided over said operating shafts; windows provided insaid cover plate having a length corresponding to the moving stroke ofsaid sliding members; an indicator plate disposed upwardly from saidoperating shafts and making a predetermined angle with said operationalshafts; windows in said indicating plate corresponding to theabove-mentioned windows in said cover plate; and flexible ribbons eachextending along one of said windows in the indicating plate and alsoalong the corresponding window in said cover plate in sliding manner,and one end thereof being fixed to a corresponding one of the slidingmembers; whereby the movement of said sliding members on the operatingshafts can be indicated by the movement of ribbons in said windows inthe indicating plate attached on the front part of the control device.11. A control device as defined in claim 10, wherein each of saidribbons is received in a groove provided beside each window and ismovable along said groove.